Source: ISO

Having access to safe and nutritious food is essential. Meat, fish, dairy products, eggs, shellfish, etc., contain significant microbial flora and this can affect our health. Therefore, it is important to identify the microorganisms to maintain food safety but the microbial flora can also affect, if not controlled, the quality of food and its shelf life. Whether you are a manufacturer or user of microbiological test methods, you want to ensure that your methods are fully tested, validated and fit for use.

International Organization for Standardization (ISO) 16140:2003 for the validation of alternative (proprietary) microbiological methods has just been revised. The new multipart standard provides a specific protocol and guidelines for the validation of methods both proprietary (commercial) or not. Proprietary methods are generally cheaper to use, produce results faster than traditional culturing methods and are simpler to perform as they require fewer technical skills. What’s more, most are partly or completely automated, so easier to use in less experienced laboratories, such as factory and commercial laboratories and with less technical human resources.

Two parts of ISO 16140 series now published
ISO 16140-1:2016, Microbiology of the food chain – Method validation – Part 1: Vocabulary, describes the terminology used in microbial testing, while ISO 16140-2:2016, Microbiology of the food chain – Method validation – Part 2: Protocol for the validation of alternative (proprietary) methods against a reference method, is dedicated to the validation of proprietary microbiological methods. They are designed to help food and feed testing laboratories, test kit manufacturers, competent authorities, and food and feed business operators to implement microbiological methods. ISO 16140-2 includes two phases, the method comparison study and the interlaboratory study, with separate protocols for the validation of qualitative and quantitative microbiological methods.

New validation insights included
Over a hundred alternative methods have been validated based on the previous version of ISO 16140, and the standard was updated to provide new insights on the validation of microbiological methods and experience gained from conducting validation studies across the world. Today, many alternative (mostly proprietary) methods exist that are used to assess the microbiological quality of raw materials and finished food products and monitor the microbiological status of manufacturing processes. The developers, end-users and authorities need a reliable common protocol for the validation of such alternative methods. With this new protocol, the data generated will also provide potential end-users with performance data for a given method, thus enabling them to make an informed choice on the adoption of a particular (alternative) method. This data can also serve as a basis for the certification of a method by an independent organization.

Development of ISO 16140 series
“The validation according to ISO 16140-2 will lead to a higher reliability of the alternative method test result and the users will benefit from having microbiological test results available sooner. Most likely, this will contribute to greater food safety,” explained Paul in ‘t Veld, the Convenor of Working Group 3 on method validation (ISO/TC 34/SC 9/WG 3 whose secreteriat is held by NEN, ISO member for the Netherlands) that is responsible for the development of the ISO 16140 series. The other four new parts of ISO 16140 are still under development with the following topics:

Protocol for the verification of reference and validated alternative methods implemented in a single laboratory (Part 3 of ISO 16140)

Protocol for single-laboratory (in-house) method validation (Part 4 of ISO 16140)

Protocol for factorial interlaboratory validation for non-proprietary methods (Part 5 of ISO 16140)

Protocol for the validation of alternative (proprietary) methods for microbiological confirmation and typing (Part 6 of ISO 16140)

WG 3, Method validation, is part of the subcommittee ISO/TC 34/SC 9, Food products – Microbiology, whose secretariat is held by AFNOR, ISO member for France. The standard is available from your national ISO member or on the ISO Store.